Syntheses, Weak Interactions, and Crystal Structures of Two Tetrabromocuprate(II) Complexes Containing Benzyl Substituted Alkyl Pyridinium

Abstract

Two tetrabromocuprate(II) complexes containing substituted benzyl alkyl pyridinium, [Bz-4-MePy]₂[CuBr₄] (1) and [Bz-4-EtPy]₂[CuBr₄] (2) ([Bz-4MePy]⁺ = (1-benzyl-4′-methylpyridinium) [Bz-4-EtPy]⁺ = 1-benzyl-4′-ethylpyridinium), were crystallized from methanol and dilute HBr solutions, and were determined by single crystal X-ray diffraction. Two complexes crystallize in the orthorhombic system with space group Pna2₁, and comprise two tortuous cations and one tetrahedral [CuBr₄]^2– anion. The [CuBr₄]^2– anions in two complexes form a linear chain by Br···Br interaction with the distance of 4.001 Å for 1 and 4.062 Å for 2, while the combination of C‒H···Br and C‒H···N weak hydrogen bonds, p···π and π···π, interactions consolidate the crystal packing and results in a 3D network structure.

Keywords:

• benzyl substituted alkyl pyridinium
• crystal structures
• tetrabromocuprate(II) anion
• weak interactions

Acknowledgments

This work has been partially supported by the Science and Technology Project (Nos. 2011B080701026 and 2012B010200041) from Guangdong Science and Technology Department, the Undergraduates’ Innovative Experimental Program in University from Department of Education of Guangdong province (No. 1056413047), and the key Academic Program of the 3rd phase “211 Project” of South China Agricultural University (No. 2009B010100001).